As a reminder, take note that inside your main transmission, things are going round and round, such as your planetary and sun gears, just to name a couple. For good preventative maintenance you may want to take a look at all the pieces bolted together such as the mast retainer plate, top case, ring gear case, main case, support case and so forth. As a precaution, do a torque check on the fasteners holding the case pieces together. Don't forget your quills either, such as your offset quill. It has to hold that generator while it is spinning. Remember this about all quills, they hold things that spin. Also make sure the breather holes are clear and not clogged.